A CATHETER OR CANNULA SYSTEM

Abstract: A catheter or cannula (2) which includes a press or pinch point (18) which may be resiliently deformed to prevent flow of blood or other body fluids during insertion of the catheter or cannula tube (10) or it may be part of the boss (11) of the catheter or cannula (2). One or more protrusions or buttons (20) may be integrally moulded to the press or pinch point (18) to assist with the application of pressure to the press or pinch point (18) to prevent fluid flow. Wings (14) extending from the sides of the cannula or catheter (2) may provide support and be hinged to enable compression of the press or pinch point (18). The cathether or cannula tube (10) is of a size to fit over a hypodermic needle (5) of a trocar (1) inserted into the catheter or cannula (2).

Description: A CATHETER OR CANNULA SYSTEM TECHNICAL FIELD This invention relates to an improvement to systems which use an artificial tube for supply to or extraction of fluids from a human or animal body. BACKGROUND ART The insertion of a tube into a human or animal in many cases requires a hole to be pierced through the skin. For this purpose a device known as a trocar, a catheter or a cannula may be used. A trocar is a sharp pointed instrument adapted to punch the wall of the body. The trocar may have a catheter or cannula mounted onto it and upon removal of it from the catheter or cannula fluid may be extracted. A catheter is a tubular flexible instrument passed into a body cavity or channel for withdrawal of fluids from or introduction of fluids into the body cavity or channel. A cannula is for inserting into a duct or cavity in a body. During it's insertions it lumen may be occupied by a stylet or trocar. A stylet is a wire adapted to run through a catheter or cannula to render it stiff or to remove debris from its lumen. One specialized form of trocar or stylet is a hypodermic needle having a splash back with a window so that during insertion when blood is seen in the window it is known that a vein or artery has been pierced. Generally in this specification the word cannula will be used to describe either a catheter or cannula and trocar will be used to define a trocar, stylet or splash back. Generally a catheter or cannula with a stylet or trocar or combination of these is used as an artificially inserted tube into a human or animal body either for the delivery of fluids into the body or the removal of fluids from the body. In one method a catheter or cannula assembly is inserted into a vein of an animal or human and the trocar or stylet is removed to leave the cannula or catheter in place. At the time of removal of the catheter or cannula there can be a problem with loss of blood and perhaps of more concern a danger with infection by blood or body fluid borne diseases. In the past there has been no reasonable solution to prevent this loss of blood. It is the object of this invention to provide an arrangement by which the loss of blood or other body fluids is able to be restricted during the process of insertion of an artificial tube such as a catheter or cannula assembly into a human or animal body. DISCLOSURE OF THE INVENTION In one form the invention is said to reside in an arrangement including an artificially insertable catheter or cannula for insertion into a human or animal body, the catheter or cannula including a flow path therethrough for supply to or extraction of blood or other fluids from the human or animal body, the invention being characterised by the catheter or cannula including a press point adapted to be pressed to stop flow of fluid through the flow path. The press point may be associated with the catheter or cannula assembly or may be as an attachment which can be fastened onto a catheter or cannula assembly. It will be seen that generally by this invention, that the press point can be used after the insertion of the catheter or cannula assembly and during removal of a trocar or stylet used to make the catheter or cannula rigid during insertion to stop blood flow until a suitable connection has been made to the catheter or cannula for whatever purpose. When in the non-pinched state the pinch point of course does not provide any restriction to the insertion of the hypodermic needle of the stylet, trocar or splash back. In an alternative form the invention may be said to reside in a catheter or cannula assembly of the type having a catheter or cannula mounted or a stylet or trocar, the catheter or cannula including a flowpath therethrough and at least one portion of the catheter or cannula being adapted to be manually resiliently deformed to close off the flow path after removal of the stylet or trocar. The catheter or cannula may generally be of a type including a boss, a tube and a connecting portion. The at least one portion which is adapted to be resiliently deformed may be at the base of the tube adjacent the boss, or alternatively the portion may be included as part of the boss or may be between the boss and the connecting portion. This resiliently deformable portion of the catheter or cannula may be made from a flexible or elastomeric or plastics material such as silicone rubber . Alternatively the portion of the catheter or cannula which is adapted to be resiliently deformed can be an adaptor piece which can be fitted to an existing catheter or cannula by the use of known types of medical connectors for provision of a pinch point onto such an item. In an alternative form the invention may be said to reside in a catheter or cannula, the catheter or cannula including a boss and a tube, the boss including a first portion into which the tube is mounted and a connection portion which enables the catheter or cannula to be connected to another item, characterised by a pinch point between the first portion and the connector portion, the pinch point being adapted to be pinched to restrict flow through the catheter or cannula. The pinch point may be a soft flexible plastics material or rubber portion. The entire boss may be made of a soft flexible rubber or plastics material and be adapted to be resiliently deformed to provide the pinch point. Alternatively the first portion and the connector portion may be connected by a frame assembly with the pinch portion being a soft flexible rubber or plastics material tube received into the frame assembly between the first portion and the connector portion and sealingly engaging the first portion and the connector portions respectively. The pinch portion may comprise merely a tube portion or a tube with one or two projections or buttons extending from it to enable more positive compression of the tube and so as to ensure that the fingers of a user are well away from the point of the stylet, trocar or splash back. In an alternative embodiment the pinch portion may include a more positive action arrangement obtained from valve pieces which can be squeezed together to more positively close off the flow path. Such valve pieces may be spring loaded and biased towards a valve open position so that upon release of the pinch portion, the tube will open again for transfer of fluids into or out of the body. When in the open position the stylet or trocar or hypodermic needle may be inserted between the valve pieces. The catheter or cannula arrangement of the present invention may include wings extending from the sides of the catheter or cannula to bear against the body of a person or animal into which the catheter or cannula is being inserted to provide a stable operating surface for the activation of the press point. In one embodiment the wings may be hinged on hinge axes aligned with the length of the catheter or cannula and may be hinged to bear against the pinch point and resiliently deform the press point. The artificial tube, catheter or cannula according to this invention may be used to enable closing off of blood flow during insertion of an intravenous cannula. Such an intravenous catheter or cannula may be used for an intravenous drip, anaesthetic supply, saline drip, addition of blood expanders or pharmaceuticals or may be used for such things as urinary catheters, wound drains, naso-gastric tubes or naso-oral-gastric tubes or any other tube through which fluids may flow. It may be particularly noted that the present application may have veterinary applications as well as applications with the human body. This then generally describes the invention but to assist with understanding the invention reference will now be made to the accompanying drawings which show preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings FIG 1 shows a perspective view of a first embodiment of a catheter or cannula assembly of the present invention, FIG 2 shows a side view of the embodiment shown in FIG 1 , FIG 3 shows a cross sectional view of the embodiment of FIG 1 , FIG 4A to 4C shows a cross-sectional view of an alternative embodiment of a catheter or cannula assembly according to this invention in various stage of operation, FIG 5A to 5F shows a cross-sectional view of an alternative embodiment of a catheter or cannula assembly according to this invention in various stage of operation, FIG 6A and 6B show a side view of an alternative embodiment of a catheter or cannula assembly according to this invention, FIG 7 shows an alternative embodiment of a pinch point arrangement of the present invention in this case being on an attachment for a catheter or cannula assembly, FIG 8 shows a further embodiment of press point on an attachment of the present invention, FIG 9 shows the embodiment of FIG 8 in cross section fully compressed, FIG 10 shows a perspective view of an alternative embodiment of a catheter or cannula of the present invention, FIG 11 shows a transverse cross sectional view of the cannula of FIG- 10, and FIG 12 , shows a transverse cross sectional view of the catheter or cannula of FIG 10 with the pinch point compressed. BEST MODE FOR CARRYING OUT THE INVENTION Now looking more closely at the drawings and in particular the embodiment shown in Figures 1 to 3 the cannula assembly of this embodiment comprises a trocar generally shown as 1 inserted into a cannula generally shown as 2. The trocar comprises a hypodermic needle 5 mounted into a base 6. The base 6 includes a translucent or transparent window portion 7. The cannula includes a cannula tube 10 generally of a plastics material and of a size to just fit over the hypodermic needle 5 of the trocar 1. The cannula tube 10 is fitted into a boss 11 on the cannula body 13 by means of a conical stainless steel clamping ring 12. The body 13 of the cannula includes wings 14 extending out to each side of the body. The body 13 terminates in a connecting portion 16 into which some item of medical equipment such as an intravenous drip tube connector may be inserted. The body includes within it a resilient tube 18 with an aperture 19 therethrough large enough for insertion therethrough of the hypodermic needle 5. The tube portion 18 includes a button 20 integrally moulded into it extending through an aperture 21 in the body 13. When the hypodermic needle 5 of the trocar 1 is not inserted into the cannula 2 then pressure on the button 20 can close off the flow path through the cannula defined by the tube 18. In use therefore with the cannula and trocar assembly joined together the hypodermic needle is inserted into the body of a patient and during insertion observation of the window portion 7 is made so that when blood is seen it will be realised that a vein has been located. During insertion the cannula and trocar are held together by the finger grips 22 and 23. The cannula is then held in place by means of fingers on the wings 14 and finger grip 23 thumb grip 22 while withdrawing the trocar from the assembly and maintaining pressure on the button 20 until the needle 5 has been removed and the pressure on the button 20 closes off the flow path through the cannula. A suitable item of medical equipment such as an intravenous drip tube connector is then connected to the connecting portion 16. Adhesive tape may be taped over the wings 14 onto the body of the patient to hold the cannula in place. The embodiment shown in Figures 4A to 4C comprises a catheter 31 and a trocar 30. The trocar includes a hypodermic needle 32 mounted into the base 33 of the trocar 30. The boss 34 of the cannula is comprised of flexible plastics material so that as shown in Figure 4B as the needle 32 is removed the boss 34 can be squeezed with the fingers of one hand until shown in Figure 4C the needle 32 is completely removed and the flow path through the cannula is closed off. In the embodiment shown in Figures 5A to 5F the trocar 40 includes a hypodermic needle 41 mounted into a base 42 which includes a window 43. The cannula part as particularly seen in Figure 5F comprises a cannula tube 45 mounted into a boss 46 the boss 46 has a strap member 47 extending to a connecting portion 48 with a flexible elastomeric tube 49 extending between the boss and the connecting portion and sealably engaging to each of these. As can particularly be seen in Figures 5C and 5D as the hypodermic needle 41 is withdrawn from the cannula the flexible plastics tube 49 can be compressed until it completely closes off the flow path through the cannula until a suitable item of medical implement has been connected. Figure 6A and 6B show two views of an alternative embodiment of cannula according to this invention. In this embodiment the portion of the cannula which can be squeezed to close off the flow path includes part of the cannula tube 51 which can be compressed at the portion 52 where it mounts into the boss 53. In this embodiment the boss 53 can be made from a rigid plastics material. Figures 7, 8 and 9 show views of alternative embodiments of cannula adaptors according to this invention which can be connected into existing cannulas by means of connectors 61 and 62 at each end of the body 60. The body includes a portion 64 which can be squeezed as in Figure 7. Figure 8 includes a portion 65 which has a button which can be pressed to close off the flow path. The cross section shown in Figure 9 includes two buttons 66 which can be squeezed together to close off the flow path. Figures 10, 11 and 12 show an alternative embodiment of a cannula according to this invention. In this embodiment the cannula 70 includes a boss 71 and a frame assembly 72 and 74 connected to a connection portion 73. Between the boss 71 and the connection portion 73 is a flexible tube 75 which is adapted to be compressed to close off the flow path. The frame portion 74 includes wings 76 and 77 which are hinged to the frame portion 74 by means of integral hinges 78. When it is desired to close off the flow path rather than squeezing the tube 75 directly the wings 76 and 77 may be hinged about the hinges 78 on the frame portion 74 so that the protuberances 79 on each wing actually compress the tube 75 to close it off. By this means a more even pressure may be applied to the tube 75. It will be realised that other embodiments of flexible tube as shown in the various embodiments of this invention may be used and rather than being of an elastic material the tube may include other means by which deformation may occur to close off the flow path. Such other means may include a helical or coiled spring which can be deformed to close off the flow path. Throughout this specification and the claims that follow unless the context requires otherwise, the words 'comprise' and 'include' and variations such as 'comprising' and 'including' will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims: 1. An artificially insertable cannula or catheter for insertion into a human or animal body, the catheter or cannula including a flow path therethrough for supply to or extraction of blood or other fluids from the human or animal body, the invention being characterised by the catheter or cannula including a press point adapted to be pressed to stop flow of fluid through the flow path. 2. An artificially insertable cannula or catheter as in Claim 1 wherein the press point is adapted to be pressed by at least one finger of a person inserting the tube. 3. An artificially insertable cannula or catheter as in Claim 1 wherein the press point is included on an attachment which is adapted to be fastened onto the cannula. 4. A catheter or cannula assembly of the type to be mounted on to a trocar the catheter or cannula including a flowpath therethrough and at least one portion of the catheter or cannula being adapted to be manually resiliently deformed to close off the flow path after removal of the trocar. 5. A catheter or cannula assembly as in Claim 4 wherein the catheter or cannula is of a type including a boss, a tube and a connecting portion and the at least one portion which is adapted to be resiliently deformed is at the base of the tube adjacent the boss. 6. A catheter or cannula assembly as in Claim 4 wherein the catheter cannula is of a type including a boss, a tube and a connecting portion and the at least one portion which is adapted to be resiliently deformed is part of the boss. 7. A catheter or cannula assembly as in Claim 4 wherein the catheter cannula is of a type including a boss, a tube and a connecting portion and the at least one portion which is adapted to be resiliently deformed is between the boss and the connecting portion. 8. A catheter or cannula assembly as in Claim 7 wherein the resiliently deformable portion of the catheter cannula is comprised of a flexible or elastomeric or plastics material such as silicone rubber . 9. A catheter or cannula assembly as in Claim 4 wherein the portion of the catheter or cannula which is adapted to be resiliently deformed is an adaptor piece adapted to be fitted to a catheter or cannula. 10. A catheter or cannula assembly, the catheter or cannula including a boss and a tube, the boss including a first portion into which the tube is mounted and a connection portion which enables the catheter cannula to be connected to another item, characterised by a pinch point between the first portion and the connector portion, the pinch point being adapted to be pinched to restrict flow through the cannula. 1 1. A catheter of a catheter or cannula assembly as in Claim 10 wherein the pinch point is comprised of a soft flexible plastics material or rubber material. 12. A catheter of a catheter or cannula assembly as in Claim 10 wherein the boss is made of a soft flexible rubber or plastics material and is adapted to be resiliently deformed to provide the pinch point. 13. A catheter or cannula assembly as in Claim 10 wherein the first portion and the connector portion are connected by a frame assembly and the pinch point is included on a soft flexible rubber or plastics material tube received into the frame assembly between the first portion and the connector portion and sealingly engaging the first portion and the connector portions respectively. 14. A catheter of a catheter or cannula assembly as in Claim 10 wherein the pinch point includes one or more projections or buttons extending from it to enable more positive compression of the tube. 15. A catheter or cannula assembly as in Claim 10 wherein the pinch point includes valve pieces which can be squeezed together to more positively close off the flow path. 16. A catheter or cannula assembly as in Claim 10 wherein the cannula includes wings extending from the sides of the cannula. 17. A catheter or cannula assembly as in Claim 16 wherein the wings are hinged on hinge axes aligned with the length of the catheter or cannula and are adapted to be hinged to bear against the pinch point and resiliently deform the pinch point to thereby restrict flow in the catheter or cannula.

Inventors: POWELL ANDREW ROBERT, POWELL, ANDREW, ROBERT
Applicants: PARASHAR HOLDINGS PTY LTD, POWELL ANDREW ROBERT, PARASHAR HOLDINGS PTY. LTD., POWELL, ANDREW, ROBERT
Application year: 1994
Main classification: A61M25
IPC codes: A61M5, A61M25, A61M39